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'(No Model.)

A. J. Q. KNOWLTON. ROLLER BUSHING FOR SHEAVES No. 594,357. Patented-Nov. 23, 1897.

WITNESSES.

To all whom it may concern:

NITED STATES PATENT Enron.

ALONZO J. Q. KNOWLTON, OF CAMDEN, MAINE, ASSIGNOR TO THE DUPLEX ROLLER BUSHINGS COMPANY, OF SAME PLACE.

ROLLER-BUSHING FOR SHEAVES.

SPECIFICATION forming part of Letters Patent No. 594,357, dated November 23, 1897. Application filerl March 15, 1897. Serial No. 627,684. (No model) Be it known that I, ALONZO J. Q. KNOWL- TON, of Camden, in the county of Knox and State of Maine, have invented certain new and useful Improvements in Roller-Bushings for Sheaves, of which the following is a speci- 'fication.

ing my invention, the end cap of the bushing having been removed to expose the rollers. Fig. 2 is a section on line 2 2 of Fig. 1. Fig. 3 is a side elevation of the cap, showing its inner side.

The same letters of reference indicate the same parts in all the figures.

Referring to the drawings, or represents a cylindrical metallic casing inserted in a central opening of the sheave b and secured thereto by transversely-extending screws 0,

whose ends screw into an outer flange a of the casing. These screws serve also to secure the cap 01 to the casing a, the said cap being provided with suitable holes (1 to receive the screws. The casing 00 and its cap d together form a box in which are contained the bearing-rollers e and g. The rollers e bear upon the block-shaft f and upon the inner wall of the casing, and each roller is provided with trunnions e e, which are adapted to engage annular ribs a and 01 formed, respectively, on the end wall a of the casing and on the cap d, this arrangement serving to retain the rolls in the casing when for any reason the sheave is removed from its shaft. The cap 01 is provided with an annular abutment 01 which bears on the outer surface of the casing a. at the open end of the latter and prevents said casing from spreading at its open end under the pressure to which it is subjected when in use. Thus far the con struction agrees with that recited in the patent before referred to. In said patent the cap cl was provided with a wide recess extending from the abutment d to the trunnionengaging rib d, and the end wall a of the casing was provided with a similar wide recess extending from the transverse or side wall of said casing to the annular rib a It has been found that this affords insufficient end bearing for the rollers c. In practice the rollers by skewing or tilting would become unevenly worn and would likewise wear away the interior of the casing unevenly, so as to impair the parallel alinement of the rollers with the axis of the central spindle f, which is necessary to the best working results.

v It is one object of the present invention to overcome this difficulty, and I do so by providing annular abutments a d on the inner faces of the end wall a and the cap d, respectively, which abutments constitute end bearings for the rollers e. Narrow recesses e are left in both the cap and the end wall of the casing, which constitute runways for the trunnions e and assist in reventin tiltin a of the rollers 6. This provision of the abutments 01. d besides affording the advantages stated, serves to give additional strength to the casing and its cap to withstand the rough usage to which the said parts may be subjected.

The small rollers g, as in the former patent referred to, are preferably composed of inoxidizable metal, such as bronze, and they act to separate the rollers e from each other and to clean or wear off any accumulation of rust that may form on the surfaces of the said larger rollers, which are preferably composed of steel.

I claim A sheave or pulley having a central cavity, a bushing or casing inserted in said cavity and having at one end an integral inwardlyprojecting flange forming the fixed end wall of a roller-holding space within said casing, and an annular end piece or cap of larger di ameter than the casing and attached outside abutments and ribs together constituting adequate end bearings for the said rollers.

In testimony whereof I have signed my name to this specification, in the presence of IS two subscribing Witnesses, this 22d day of February, A. D. 1897.

ALONZO J. Q. KNO\VLTON.

\Vitnesses:

H. T. CRAWFORD, F. I. Coonns. 

